Maximum Drill Chuck Capacity Inch 38 Minimum Drill Chuck Capacity Inch 164 Mount Type Taper Mount Mounting Size JT33 Keyless chucks are engineered to quickly loosen and tighten a tool on the chuck collar of the drill, either by manual operation or when torque is applied Rotating the chuck collar in a counterclockwise direction will loosen the tool High precision, premium tolerance The jaws feature a TIN coated surface treatment to assure durability.